INSECT PESTS OF CARROTS IN ORGANIC SOILS OF SOUTHWESTERN QUEBEC WITH SPECIAL REFERENCE TO THE CARROT WEEVIL, LISTRONOTUS OREGONENSIS (COLEOPTERA: CURCULIONIDAE)

1971 ◽  
Vol 103 (10) ◽  
pp. 1441-1448 ◽  
Author(s):  
J. P. Perron

AbstractA survey of the insect pests of carrots was conducted in the organic soils of southwestern Quebec with a view to establishing the presence of the carrot weevil, Listronotus oregonensis (Lec.), in this province as well as to confirm the importance of other pests damaging carrot crops. Four different methods were used to capture adults, and the root sampling method was used for establishing larval populations.The carrot weevil was captured by light trap for the first time in Quebec on 1 June 1967, but was neither recognized nor identified until June 1970 when a few specimens were obtained again by light trap set at Ste. Clotilde and by colour traps placed in the experimental fields used for the survey in 1970. Damage caused by this new pest on carrots ranged from 2.0% to 22.0% root injuries throughout the carrot growing areas of the organic soil regions of Sherrington, St. Michel, and Ste. Clotilde representing several thousands of acres. The carrot rust fly, Psila rosae (F.), was the only other carrot pest captured, but has been found to be of no importance in these areas.

2017 ◽  
Vol 149 (5) ◽  
pp. 592-599 ◽  
Author(s):  
Robert J. Lamb ◽  
Guy Boivin

AbstractLong-term, twice weekly, trap catches of the native carrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae), and the introduced carrot rust fly, Psila rosae (Fabricius) (Diptera: Psilidae), were used to test the hypothesis that native populations fluctuate less from year-to-year than those of introduced species, because the native species has had more time to adapt to temporal variability in its habitat than an introduced species. Variability in annual abundance was estimated for 33 years, and for 11-year or 16–17-year subsets of the 33-year time series. Temporal population variability was quantified as PV, a proportion between 0 and 1. The native carrot weevil had a PV of 0.39, less than that of the introduced carrot rust fly with a PV of 0.67, supporting the hypothesis. Generation 1 for both species showed a decline in PV over three decades consistent with the hypothesis that adaptation to variability in the habitat leads to lower PV. Over 33 years, the carrot weevil developed a second generation with a PV of 0.70, higher than that of the first generation, which is consistent with the hypothesis that adaptation is required to stabilise population dynamics in a new habitat, in this case a new temporally defined habitat.


2020 ◽  
Vol 4 (2) ◽  
pp. 392-400
Author(s):  
O. S. Balogun ◽  
M. A. Damisa ◽  
O. Yusuf ◽  
O. L. Balogun

The study was carried out to examine the effect of agricultural transformation on the beneficiary’s productivity and poverty of rice farmers in Kano State Nigeria. A multi-stage sampling method was employed to select 571 respondents for the study. Data were collected through structured questionnaires on respondent’s income, input and output quantities as well as their expenditures. Data were analysis using descriptive statistics, Foster-Greer-Thorbecke (FGT), Propensity score matching and LATE model. Results from the study shows that respondents productivity revealed a significant difference of about 127 kg/ha in rice productivity between participants and non-participants. Also, the LATE estimates revealed an average treatment effect ATE0 of about 222.98kg/ha. Furthermore, the project had a significant effect N11, 321.4 on the participant’s consumption expenditure than the non-participants N9980.60. Moreover, participants were, able to increase their household total expenditures by N34780 per annum. Fluctuations of input/output prices insect pests and inadequate extension visits were all the major constraints faced by the farmers. It was recommended that farmers’ information and sensitization system should be overhauled and improved. Also, attention should be given to well organize extension visits for the farmers from stake holders


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Valeria Fattoruso ◽  
Gianfranco Anfora ◽  
Valerio Mazzoni

AbstractThe greenhouse whitefly (GW), Trialeurodes vaporariorum is considered one of the most harmful insect pests in greenhouses worldwide. The GW mating behavior has been partially investigated and its vibrational communication is only in part known. A deeper knowledge of its intraspecific communication is required to evaluate the applicability of control methods based on techniques of behavioral manipulation. In this study, for the first time, we provided a detailed ethogram of the GW mating behavior and we characterized the vibrational signals emitted during the process of pair formation. We characterized two types of male vibrational emissions (“chirp” and “pulses”), differently arranged according to the behavioral stage to form stage-specific signals, and a previously undescribed Male Rivalry Signal. We recorded and characterized two new female signals: The Female Responding Signal and the Female Rejective Signal. The mating behavior of GW can be divided into six different stages that we named “call”, “alternated duet”, “courtship”, “overlapped duet”, “mating”, “failed mating attempt”. The analysis performed with the Markovian behavioral transition matrix showed that the “courtship” is the key stage in which male exhibits its quality and can lead to the “overlapped duet” stage. The latter is strictly associated to the female acceptance and therefore it plays a crucial role to achieve mating success. Based on our findings, we consider the use of vibrational playbacks interfering with GW mating communication a promising option for pest control in greenhouses. We discuss the possibility to start a research program of behavioral manipulation to control the populations of GW.


1990 ◽  
Vol 70 (3) ◽  
pp. 363-377 ◽  
Author(s):  
D. ANN BROWN ◽  
S. P. MATHUR ◽  
ANTON BROWN ◽  
D. J. KUSHNER

Different numerical methods used to distinguish between organic soil types are evaluated. The research was initiated by the suggestion that acid leaching from mining wastes could be prevented by capping the tailings with a self-renewing methane-producing muskeg bog, in order to prevent the penetration of oxygen to the wastes. Thirty organic soils from bogs in the mining districts of Elliot Lake, Sudbury, and Timmins, Ontario, and Noranda, Quebec, were sampled and 28 soil characteristics were measured. These characteristics, whose values are normally or lognormally distributed, were analyzed by several different statistical methods. Some characteristics indicate the existence of two populations, and others are bivariantly correlated. Canonical discriminant analysis was more successful than cluster analysis in separating the bogs into well-defined geographical groups. However, principal component analysis proved best at grouping the organic soils according to their organic and inorganic components, and we suggest that this is a suitable method for the general discrimination of organic soil types. Methane was present in all the 17 bogs tested for it, and in two very wet bogs more than 2 mmol of methane per liter were extracted. Key words: Muskeg bog, organic soils, soil characterization, principal component analysis


2021 ◽  
Vol 11 (5) ◽  
pp. 1980
Author(s):  
Kazimierz Józefiak ◽  
Artur Zbiciak ◽  
Karol Brzeziński ◽  
Maciej Maślakowski

The paper presents classical and non-classical rheological schemes used to formulate constitutive models of the one-dimensional consolidation problem. The authors paid special attention to the secondary consolidation effects in organic soils as well as the soil over-consolidation phenomenon. The systems of partial differential equations were formulated for every model and solved numerically to obtain settlement curves. Selected numerical results were compared with standard oedometer laboratory test data carried out by the authors on organic soil samples. Additionally, plasticity phenomenon and non-classical rheological elements were included in order to take into account soil over-consolidation behaviour in the one-dimensional settlement model. A new way of formulating constitutive equations for the soil skeleton and predicting the relationship between the effective stress and strain or void ratio was presented. Rheological structures provide a flexible tool for creating complex constitutive relationships of soil.


2020 ◽  
Vol 2 (2) ◽  
pp. 72-78
Author(s):  
A.S. Sazhnev ◽  
◽  
V.V. Anikin ◽  

The article presents the results of research of the using light traps (luminescent lamp Actinic 6W) for collecting Coleoptera in the Saratov city. Entomological material was collected by the second author in the period from 1.06 to 2.10.2019. In 2019, 52 species of Coleoptera of 22 families from different ecological groups were recorded. A relatively high proportion of adventitious species remains in 17.3– 30.7% of the presented fauna was presented. For two years the 14 species of alien and cryptogenic Coleoptera species were observed, that is 24.5% of the adventive fauna of the Saratov Province. Among invasive species Attagenus smirnovi, Stegobium paniceum, Atomaria lewisi, Harmonia axyridis, Gnatocerus cornutus, and Orchestes steppensis were record for the first time in 2019. It to use bringing on light as one of the available and low-cost ways to identify alien and cryptogenic organisms in urban areas is recommended.


2013 ◽  
Vol 13 (1) ◽  
pp. 349-352
Author(s):  
Sérgio Roberto Rodrigues ◽  
Anderson Puker

Coleoptera of the family Geotrupidae play an important ecological role in the decomposition of animal and plant organic matter. In Brazil there is little information on the diversity and distribution of this group, thus, this work had a purpose to study Geotrupidae species, occurring in Aquidauana, MS. A survey for geotrupids was conducted in Aquidauana, Mato Grosso do Sul, Brazil. Beetles were captured using a light trap over a period of two years, from January 2006 to December 2007. A total of 907 specimens were collected and identified to eight species. From the subfamily Bolboceratinae, the species identified were Bolbapium minutum (Luederwaldt, 1929) and Pereirabolbus castaneus (Klug, 1845). In the subfamily Athyreinae the species identified were Athyreus bilobus Howden & Martínez, 1978, Parathyreus aff. bahiae, Neoathyreus aff. julietae, N. sexdentatus Laporte, 1840, N. centromaculatus (Felsche, 1909) and N. goyasensis (Boucomont, 1902). Four species (A. bilobus, N. centromaculatus, N. goyasensis and P. castaneus) are reported for the first time in Aquidauana, MS, Brazil. The most abundant species, representing 85.9% of the total capture, was B. minutum. The greatest numbers of specimens was caught from October to December of both years of the study.


2013 ◽  
Vol 10 (11) ◽  
pp. 7739-7758 ◽  
Author(s):  
A. Meyer ◽  
L. Tarvainen ◽  
A. Nousratpour ◽  
R. G. Björk ◽  
M. Ernfors ◽  
...  

Abstract. Afforestation has been proposed as a strategy to mitigate the often high greenhouse gas (GHG) emissions from agricultural soils with high organic matter content. However, the carbon dioxide (CO2) and nitrous oxide (N2O) fluxes after afforestation can be considerable, depending predominantly on site drainage and nutrient availability. Studies on the full GHG budget of afforested organic soils are scarce and hampered by the uncertainties associated with methodology. In this study we determined the GHG budget of a spruce-dominated forest on a drained organic soil with an agricultural history. Two different approaches for determining the net ecosystem CO2 exchange (NEE) were applied, for the year 2008, one direct (eddy covariance) and the other indirect (analyzing the different components of the GHG budget), so that uncertainties in each method could be evaluated. The annual tree production in 2008 was 8.3 ± 3.9 t C ha−1 yr−1 due to the high levels of soil nutrients, the favorable climatic conditions and the fact that the forest was probably in its phase of maximum C assimilation or shortly past it. The N2O fluxes were determined by the closed-chamber technique and amounted to 0.9 ± 0.8 t Ceq ha−1 yr−1. According to the direct measurements from the eddy covariance technique, the site acts as a minor GHG sink of −1.2 ± 0.8 t Ceq ha−1 yr−1. This contrasts with the NEE estimate derived from the indirect approach which suggests that the site is a net GHG emitter of 0.6 ± 4.5 t Ceq ha−1 yr−1. Irrespective of the approach applied, the soil CO2 effluxes counter large amounts of the C sequestration by trees. Due to accumulated uncertainties involved in the indirect approach, the direct approach is considered the more reliable tool. As the rate of C sequestration will likely decrease with forest age, the site will probably become a GHG source once again as the trees do not compensate for the soil C and N losses. Also forests in younger age stages have been shown to have lower C assimilation rates; thus, the overall GHG sink potential of this afforested nutrient-rich organic soil is probably limited to the short period of maximum C assimilation.


2015 ◽  
Vol 18 (2) ◽  
pp. 132-144
Author(s):  
Trang Thi Nhu Tran ◽  
Ty Thi Pham ◽  
Hai Lam Son Truong

The first time in Vietnam a passive sampling method has been developed to analyse the polar pesticides in surface water. The initial investigations of POCIS were performed for 7 polar pesticides as simazine,thiodicarb, carbofuran, chlortoluron, atrazine, isoproturon, and diuron. We determined the sampling rates RS for these substances ranged from 0.369 to 0.962 L day- 1. The obtained values of ku and RS showed the important influence of environmental factors such as flow on the ability to integrate polar pesticides in passive sampling process. This method can be applied to determine these 7 polar pesticides in surface water at trace levels according to European standards for pesticide residues in water (< 0.1 μg L-1).


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